1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Licensed under the Apache License, Version 2.0 (the "License");
4 # you may not use this file except in compliance with the License.
5 # You may obtain a copy of the License at
7 # http://www.apache.org/licenses/LICENSE-2.0
9 # Unless required by applicable law or agreed to in writing, software
10 # distributed under the License is distributed on an "AS IS" BASIS,
11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 # See the License for the specific language governing permissions and
13 # limitations under the License.
15 # Instantiation and transformation of semantic nodes in the AST of expressions and statements
19 intrude import literal
23 # General factory to build semantic nodes in the AST of expressions
25 # The module used as reference for the building
26 # It is used to gather types and other stufs
29 # The anchor used for some mechanism relying on types
30 var anchor
: nullable MClassType
32 # Make a new Int literal
33 fun make_int
(value
: Int): AIntExpr
35 return new ADecIntExpr.make
(value
, mmodule
.get_primitive_class
("Int").mclass_type
)
38 # Make a new instatiation
39 fun make_new
(callsite
: CallSite, args
: nullable Array[AExpr]): ANewExpr
41 return new ANewExpr.make
(callsite
, args
)
44 # Make a new message send
45 fun make_call
(recv
: AExpr, callsite
: CallSite, args
: nullable Array[AExpr]): ACallExpr
47 return new ACallExpr.make
(recv
, callsite
, args
)
50 # Make a new, empty, sequence of statements
51 fun make_block
: ABlockExpr
53 return new ABlockExpr.make
56 # Make a new variable read
57 fun make_var_read
(variable
: Variable, mtype
: MType): AVarExpr
59 return new AVarExpr.make
(variable
, mtype
)
62 # Make a new variable assignment
63 fun make_var_assign
(variable
: Variable, value
: AExpr): AVarAssignExpr
65 return new AVarAssignExpr.make
(variable
, value
)
68 # Make a new attribute read
69 fun make_attr_read
(recv
: AExpr, attribute
: MAttribute): AAttrExpr
71 var mtype
= attribute
.intro
.static_mtype
.resolve_for
(recv
.mtype
.as(not null), anchor
, mmodule
, true)
72 return new AAttrExpr.make
(recv
, attribute
, mtype
)
75 # Make a new attribute assignment
76 fun make_attr_assign
(recv
: AExpr, attribute
: MAttribute, value
: AExpr): AAttrAssignExpr
78 return new AAttrAssignExpr.make
(recv
, attribute
, value
)
81 # Make a new escapable block
84 return new ADoExpr.make
87 # Make a new condinionnal
88 # `mtype` is the return type of the whole if, in case of a ternary operator.
89 fun make_if
(condition
: AExpr, mtype
: nullable MType): AIfExpr
91 return new AIfExpr.make
(condition
, mtype
)
96 # Return a new variable read that contains the value of the expression
97 # This method take care efficiently of creating and initalising an anonymous local variable
99 # Note: since this method do side-effects (AST replacement), there could be unexpected effects when used as
100 # argument of other methods related to AST transformations.
101 fun make_var_read
: AVarExpr
103 var variable
= self.variable_cache
104 if variable
== null then
105 assert parent
!= null
106 var place
= detach_with_placeholder
107 variable
= new Variable("")
108 variable
.declared_type
= self.mtype
109 var nvar
= new AVarAssignExpr.make
(variable
, self)
110 place
.replace_with
(nvar
)
111 self.variable_cache
= variable
113 return new AVarExpr.make
(variable
, variable
.declared_type
.as(not null))
116 private var variable_cache
: nullable Variable
118 # The `detach` method completely remove the node in the parent.
119 # Owever, sometime, it is useful to keep the emplacement of the removed child.
121 # The standard usecase is the insertion of a node beetwen a parent `p` and a child `p.c`.
122 # To create the new node `n`, we need to attach the child to it.
123 # But, to put `n` where `c` was in `p`, the place has to be remembered.
127 # var h = c.detach_with_placeholder
128 # var n = astbuilder.make_XXX(c)
130 fun detach_with_placeholder
: AExpr
132 var h
= new APlaceholderExpr.make
138 # Add `expr` at the end of the block
140 # REQUIRE: self isa ABlockExpr
142 # Note: this method, aimed to `ABlockExpr` is promoted to `AExpr` because of the limitations of the hierarchies generated by sablecc3
149 # A placeholder for a `AExpr` node
150 # Instances are transiantly used to mark some specific emplacments in the AST
151 # during complex transformations.
153 # Their must not appear in a valid AST
155 # @see AExpr::detach_with_placeholder
156 class APlaceholderExpr
163 redef class ABlockExpr
169 redef fun add
(expr
: AExpr)
179 escapemark
= new EscapeMark(null, false)
182 # Make a new break expression of the given do
183 fun make_break
: ABreakExpr
185 var escapemark
= self.escapemark
186 if escapemark
== null then
187 escapemark
= new EscapeMark(null, false)
188 self.escapemark
= escapemark
190 return new ABreakExpr.make
(escapemark
)
194 redef class ABreakExpr
195 private init make
(escapemark
: EscapeMark)
197 self.escapemark
= escapemark
202 private init make
(condition
: AExpr, mtype
: nullable MType)
206 _n_expr
.parent
= self
207 _n_then
= new ABlockExpr.make
208 _n_else
= new ABlockExpr.make
221 redef class ADecIntExpr
222 private init make
(value
: Int, t
: MType)
225 self._n_number
= new TNumber # dummy
231 private init make
(callsite
: CallSite, args
: nullable Array[AExpr])
233 _n_kwnew
= new TKwnew
234 _n_type
= new AType.make
235 _n_args
= new AListExprs
237 n_args
.n_exprs
.add_all
(args
)
239 self.callsite
= callsite
240 self.mtype
= callsite
.recv
245 redef class ACallExpr
246 private init make
(recv
: AExpr, callsite
: CallSite, args
: nullable Array[AExpr])
249 _n_args
= new AListExprs
252 self.n_args
.n_exprs
.add_all
(args
)
254 var mtype
= recv
.mtype
.as(not null)
255 self.callsite
= callsite
256 self.mtype
= callsite
.msignature
.return_mtype
261 redef class AAttrExpr
262 private init make
(recv
: AExpr, attribute
: MAttribute, t
: MType)
267 mproperty
= attribute
272 redef class AAttrAssignExpr
273 private init make
(recv
: AExpr, attribute
: MAttribute, value
: AExpr)
280 _n_assign
= new TAssign
281 mproperty
= attribute
287 private init make
(v
: Variable, mtype
: MType)
295 redef class AVarAssignExpr
296 private init make
(v
: Variable, value
: AExpr)
301 _n_assign
= new TAssign